Ricerc@Sapienza

The effects of a mechanical pretreatment, carried out by a two stages mill followed by fractionation into two different products, were determined on the biodegradability and methane yield of wheat straw. Straw was chopped in a knife mill to an average length of about 30 mm, and a portion was used as reference material. Pretreatment reduced the size of the processed straw, whose median particle size was 300μm and 1200μm for the fine and the coarse fractions, respectively.

The effects of a mechanical process were determined on the solid fuel quality and anaerobic biodegradability of hazelnut and olive pruning. Both the feedstocks did not meet the specification for industrial and residential pellets given in the European Standard EN ISO 17225-2, because of too high ash and nitrogen content. The coarser products from processing were notable for the high reduction in both the ash and nitrogen content.

The effects of a mechanical pretreatment were determined on the methane yield of water hyacinth. The feedstock was pretreated using a two stages dry milling process and the experiments were performed at a mass flow rate of about 750 kg h -1 . Untreated and pretreated materials were both anaerobically digested in batch reactors under mesophilic conditions for 28 days. The cumulative biogas production from pretreated hyacinth exceeded 141.8 Nm 3 tr -1 of volatile solids, showing a +44.5% gain compared to the raw material.

The effects of an industrial scale, mechanical pretreatment were determined on the methane yield of Giant reed stems. The feedstock was pretreated using a two stages dry milling process and the experiments were performed for two different mass flow rates (600 and 900 kg h-1). Untreated and pretreated stems were both anaerobically digested in batch reactors under mesophilic conditions for 28 days. The cumulative biogas production from the pretreated materials exceeded 212 Nm3t-1of volatile solids, showing a 137% gain compared to the raw material.

The updated Bioeconomy Strategy document “A sustainable bioeconomy for Europe: strengthening the connection between economy, society and the environment”, which was issued by the European Commission in October 2018, encourages the exploitation of organic wastes according to a pyramidal hierarchy in which the extraction of valuable biomolecules, which will be used as they are or as precursors of high-added-value compounds, is a priority in biofuel production.

A combined acidic fermentation and anaerobic digestion (AD) treatment has been developed on pilot scale for urban bio-waste conversion into volatile fatty acid (VFA) and biogas. The specific waste mixture was composed by the pre-treated organic fraction of municipal solid waste (OFMSW) and waste activated sludge (WAS), both produced inside the Treviso (northeast Italy) municipality. The effect of temperature (37 °C and 55 °C) was investigated in both steps.

The aim of this work was to provide a complete exergy and energy analysis of three biogas upgrading technologies: amine scrubbing, water scrubbing and membrane separation processes. Biogas production and treatment represents a key-process for the application of Circular Economy principles, since allows to reuse/reconvert industrial by-products or agro-industrial waste in a product that can be used in different energy demanding sectors, after proper cleaning and upgrading processes.

ECONOMIC AND ENVIRONMENTAL SUSTAINABILITY OF PLANTS FOR THEPRODUCTION OF BIOGAS FROM LIVESTOCK WASTE: A CASE STUDY IN THEMUNICIPALITY OF PONTINIA.
The presence in the municipality of Pontinia of an intensive livestock activity has led to assess the possibility to realize a biogas production plant, aimed at the generation of electricity and thermal energy.

Extra virgin olive-oil (EVO) production is an important economic activity for several countries, especially in the Mediterranean area such as Spain, Italy, Greece and Tunisia. The two major by-products from olive oil production, solid-liquid Olive Pomace (OP) and the Olive Mill Waste Waters (OMWW), are still mainly disposed on soil, in spite of the existence of legislation which already limits this practice.